BACKGROUND OF THE INVENTION
1. Field of the Invention
[0001] The present invention relates to an object conveying device that mounts a conveyed
object to a predetermined position while aligning it, and particularly, to an object
conveying device that mounts a light-weight conveyed object to a predetermined position.
2. Description of the Related Art
[0002] An optical disk is generally manufactured by producing a master disk where recording
information, a file structure, disk specifications such as format specifications are
recorded on a glass substrate, and by duplicating the master disk into a plastic substrate.
[0003] In general, the duplication of the master disk into a plastic substrate is performed
by an injection molding method where a definite amount of a plastic material is injected
into a molding die having a plastic substrate shape, and cooled and solidified as
it is. For the duplication of pit shapes on an information recording surface, a stamper
is used that has replicated the pit shapes on the information recording surface of
a master disk by electroplating the information recording surface. When the above-described
injection molding is to be performed, the stamper is mounted inside the molding die
with its surface on which the pit-shapes have been replicated, faced toward the inside
of the molding die. By performing injection molding in this state, an optical disk
having desired pit shapes is produced.
[0004] The stamper used in this duplication process of the optical disk is stored for each
kind of produced optical disk, and when the plastic substrate is to be duplicated,
the stamper is replaced every time the kind of optical disk to be duplicated changes.
Generally, the mounting of the stamper at a stamper replacement is performed by using
a stamper mounting device, and the mounting of the stamper by the stamper mounting
device is performed while aligning the stamper with a predetermined position of the
molding die.
[0005] The mounting of the stamper is performed by pressing the head portion of the stamper
mounting device holding the stamper against the inside of the molding die. In this
case, the alignment of the stamper is performed by a reference pin for alignment provided
at the head portion of the stamper mounting device being guidedly inserted into a
recess of the molding die, which is a reference pin receiving hole provided inside
the molding die.
[0006] However, conventional stamper mounting devices are insufficient in the flexibility
of the head portion to position variations. As a result, when the reference pin provided
at the head portion is guided into the recess provided inside the molding die, a too
large force is applied to the contact portion between the reference pin and the molding
die recess. This raises a problem that the reference pin and/or the molding die recess
may be deformed and/or damaged.
[0007] Also, at an alignment of the stamper, when the stamper holding surface of the head
portion tilts with respect to the stamper mounting surface of the molding die, the
stamper held to the head portion is pressed against this stamper mounting surface
in a state tilting with respect to the stamper mounting surface of the molding die.
This creates a problem that the stamper may be deformed and/or damaged.
SUMMARY OF THE INVENTION
[0008] Accordingly, it is an object of the present invention to provide an object conveying
device capable of mounting a conveyed object such as a stamper to a predetermined
position while aligning it without deforming or damaging a reference pin and/or a
molding die.
[0009] It is another object of the present invention to provide an object conveying device
capable of mounting a conveyed object such as a stamper to a predetermined position
while aligning it, without deforming or damaging it.
[0010] In order to achieve the above-described object, the present invention, in a first
aspect, provides an object conveying device that mounts a conveyed object to a predetermined
position while aligning it. This object conveying device comprises a support portion
that is provided with a power to move the conveyed object; a first elastic member
held to the support portion; an aligning bearing wherein one of an inner ring and
an outer ring is held to the first elastic member; and a conveyed object holding mechanism
that holds the conveyed object, the conveyed object holding mechanism being held to
one end of the ring that is not held to the first elastic member out of the inner
and outer rings of the aligning bearing.
[0011] Herein, the first elastic member and the aligning bearing provide the conveyed object
holding mechanism with flexibility to position variations and angle variations, and
thereby corrects positional deviations and tilting of the conveyed object when aligned.
[0012] Also, the present invention, in a second aspect, provides an object conveying device
that mounts a conveyed object to a predetermined position while aligning it. This
object conveying device comprises a support portion that is provided with a power
to convey the conveyed object; a first elastic member held to the support portion;
an aligning bearing wherein one of an inner ring and an outer ring is held to the
first elastic member; a common plate held to one end of the ring that is not held
to the first elastic member out of the inner and outer rings of the aligning bearing;
a second elastic member held by the common plate; a third elastic member held by the
common plate; a tray held by the third elastic member, the tray holding the outer
peripheral portion of the conveyed object; a conveyed object holding block held by
the second elastic member, the conveyed object holding block holding the inner peripheral
portion of the conveyed object at a position projecting in the direction of the conveyed
object, over the conveyed object holding surface of the tray; a fourth elastic member
held by the conveyed object holding block ; a center guide held by the fourth elastic
member, the center guide positioning the conveyed object with respect to the conveyed
object holding block; and a reference pin held by the center guide.
[0013] Herein, by holding the outer periphery portion of the conveyed object by the tray
and holding the inner peripheral portion thereof at a position projecting in the direction
of the conveyed object over the conveyed object holding surface of the tray, the conveyed
object is held with the inner peripheral portion thereof projected further outward
than the outer peripheral portion thereof, and the first elastic member and the aligning
bearing provide the conveyed object holding mechanism and the tray with flexibility
to position variations and angle variations, thereby corrects positional deviations
and tilting of the conveyed object when aligned.
[0014] In the object conveying device according to the present invention, it is preferable
that the elastic force of the first elastic member be lower than that of the fourth
elastic member, and that the elastic force of the fourth elastic member be lower than
that of the second elastic member.
[0015] Also, in the object conveying device according to the present invention, preferably,
the conveyed object holding block holds the inner peripheral portion of the conveyed
object at a position projecting in the direction of the conveyed object over the conveyed
object holding surface of the tray, in the range of 0.8 mm to 1.3 mm.
[0016] Furthermore, in the object conveying device according to the present invention, preferably,
the conveyed object holding block holds the inner peripheral portion of the conveyed
object at a position projecting in the direction of the conveyed object over the conveyed
object holding surface of the tray, in the range of 1.0 mm to 1.1 mm.
[0017] Moreover, the object conveying device according to the present invention preferably
has a fifth elastic member that inhibits the common plate from hanging down. Also,
in the object conveying device according to the present invention, the fifth elastic
member is preferably supported by the support portion, and wherein the fifth elastic
member holds the lower portion of the common plate.
[0018] Furthermore, in the object conveying device according to the present invention, preferably,
the conveyed object is a stamper used for forming pits on an optical disk substrate.
[0019] The above and other objects, features, and advantages of the present invention will
be clear from the following detailed description of the preferred embodiments of the
invention in conjunction with the accompanying drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
[0020]
Fig. 1 is a sectional view showing the configuration of an object conveying device
according to a first embodiment of the present invention;
Fig. 2 is a sectional view of the object conveying device according to the first embodiment
of the present invention, in which the mounting operation of a stamper to a molding
die by this object conveying device is shown;
Fig. 3 is a sectional view of the object conveying device according to the first embodiment
of the present invention, in which the mounting operation of the stamper to the molding
die by this object conveying device is shown;
Fig. 4 is a sectional view of the object conveying device according to the first embodiment
of the present invention, in which the mounting operation of the stamper to the molding
die by this object conveying device is shown;
Fig. 5 is a sectional view showing the configuration of the object conveying device
according to a second embodiment of the present invention; and
Fig. 6 is a sectional view showing the VI-VI section in Fig. 5.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
[0021] Firstly, a first embodiment of the present invention will be described.
[0022] Fig. 1 is a sectional view showing the configuration of an object conveying device
1 according to the first embodiment of the present invention. In this embodiment,
a stamper 20 used for forming an optical disk is taken as an example of conveyed object,
and the object conveying device 1 is used as a device for mounting the stamper 20
to a molding die.
[0023] Referring to Fig. 1, the object conveying device 1 comprises a support portion 2
that is provided with a power to convey the conveyed object, and a case 3; a coil
spring 4 as a first elastic member held to the support portion; an aligning bearing
5a wherein one of an inner ring or an outer ring is held to the first elastic member,
and a bearing receiver 5b holding the aligning bearing 5a; a common plate 6 held to
one end of the ring that is not held to the first elastic member out of the inner
and outer rings of the aligning bearing 5a; a coil spring 7 as a second elastic member
held by the common plate 6; a coil spring 8 as a third elastic member held by the
common plate 6; a tray 9 held by a third elastic member, the tray 9 being a conveyed
object holding mechanism that holds the outer peripheral portion of the conveyed object;
a conveyed object holding block 10 held by the second elastic member, the conveyed
object holding block holding 10 being a conveyed object holding mechanism that holds
the inner peripheral portion of the conveyed object at a position projecting in the
direction of the conveyed object, over the conveyed object holding surface of the
tray 9; a coil spring 11 as a fourth elastic member held by the conveyed object holding
block 10; a center guide 12 held by the fourth elastic member, the center guide 12
positioning the conveyed object with respect to the conveyed object holding block
10; and a reference pin 13 held by the center guide 12; magnets 14a to 14c holding
the conveyed object by elastic forces; an holding pad 15a holding the conveyed object
by the suction force thereof; a suction tube mounting mechanism 15b; and a suction
tube 15c.
[0024] As shown in Fig. 1, the head support portion 2 has, for example, a columnar structure
such as a cylinder or a prism, and is provided with a power to move a stamper as a
conveyed object by a power of a motor (not shown) or the like. The material constituting
the head support portion 2 is not particularly limited. Any material that has a sufficient
mechanical strength, including stainless steel, may be used.
[0025] As illustrated in Fig. 1, the case 3 has a shape such that one open surface in e.g.,
a substantially cylindrical structure is closed, and that the side surface edge portion
on the open surface side thereof is folded back inward. The material constituting
the case 3 is not particularly limited. Any material that has a sufficient mechanical
strength, including stainless steel, may be used.
[0026] As shown in Fig. 1, the coil springs 4, 7, 8, and 11 are, for example, helical springs.
Herein, for example, the elastic force of the coil spring 4 is lower than that of
the coil spring 11, and the elastic force of the coil spring 11 is lower than that
of the coil spring 7. The coil spring 8 expands and contracts without interlocking
with the other coil springs 4, 7, and 11, and therefore, the elastic force of the
coil spring 8 is not particularly limited. Specifically, it is desirable that the
elastic forces of these coils have, for example, the following approximate values:
the coil spring 4: 0.7 kgf, the coil spring 7: 3.0 kgf, the coil spring 8: 1.3 kgf,
and the coil spring 11: 0.8 kgf. Setting the elastic forces of the coil springs 4,
7, and 11 in this manner, allows the stamper 20 to be mounted to the molding die while
being appropriately aligned. More details in this respect will be provided later.
Meanwhile, in this embodiment, although coil springs are used as elastic members,
but other springs such as plate springs or the like may be employed as elastic members.
[0027] As shown in Fig. 1, the aligning bearing 5a comprises an outer ring 5aa, which has
a substantially cylindrical structure of which the inner wall is formed into a concave
surface; an inner ring 5ac, which has a diameter smaller than that of the outer ring
5aa, and which has a substantially cylindrical structure of which the inner wall is
formed into a concave surface; and a plurality of bearing balls 5ab disposed between
the inner wall of the outer ring 5aa and the outer wall of the inner ring 5ac. Here,
the inner ring 5ac and the outer ring 5aa are arranged so as to be capable of a relative
rotating motion (a substantially relative three-dimensional rotating motion) in a
manner such that the angle formed by the central axes thereof can be displaced. In
this substantially relative three-dimensional rotating motion, it is desirable that
the aligning bearing 5a is arranged so that the solid angle rotates by approximately
5 degrees.
[0028] As illustrated in Fig. 1, the bearing receiver 5b has a substantially cylindrical
structure that has a level difference portion on the inner wall thereof, and holds
the coil spring 4 and the aligning bearing 5a by this level difference portion. The
material constituting the bearing receiver 5b is not particularly limited. Any material
that has a sufficient mechanical strength, including stainless steel, may be used.
[0029] As shown in Fig. 1, the common plate 6 has a structure wherein for example, a substantially
columnar mounting shaft 6a is provided in the vicinity of the center of one surface
side of a disk-like structure, and wherein a common plate cylinder portion 6b having
a substantially cylindrical shape is provided on the other surface side thereof. Also,
each of the inner wall and outer wall of the common plate cylinder portion 6b is formed
into a level difference shape. The material constituting the common plate 6 is not
particularly limited. Any material that has a sufficient mechanical strength, including
stainless steel, may be used.
[0030] As illustrated in Fig. 1, the tray 9 has, for example, a structure that is formed
into a substantially annular shape, and that has a shape such that one portion of
the outer periphery thereof is folded back in one direction. Also, a tray cylinder
portion 9a having, e.g., a substantially cylindrical structure of which one end is
folded back inward, is adhered to one side of the tray 9. The material constituting
the tray 9 is not particularly limited. Any material that has a sufficient mechanical
strength, including stainless steel, may be used.
[0031] As illustrated in Fig. 1, the conveyed object holding block 10 has a shape such that
a structure wherein one open surface in a substantially cylindrical structure is closed,
and wherein the side surface edge portion on the open surface side thereof is folded
back inward, and a structure wherein one open surface in the substantially cylindrical
structure is closed, and wherein the side surface edge portion on the open surface
side thereof is folded back outward, are adhered together so that the open surfaces
thereof face away from each other. The material constituting the conveyed object holding
block 10 is not particularly limited. Any material that has a sufficient mechanical
strength, including stainless steel, may be used.
[0032] As illustrated in Fig. 1, the center guide 12 has a shape, for example, such that
one open surface in a substantially cylindrical structure is closed, and that the
side surface edge portion on the open surface side thereof is folded back outward.
The material constituting the center guide 12 is not particularly limited. Any material
that has a sufficient mechanical strength, including stainless steel, may be used.
[0033] As shown in Fig. 1, the reference pin 13 has, e.g., a substantially columnar structure
of which the front end is rounded off. The material constituting the reference pin
13 is not particularly limited. Any material that has a sufficient mechanical strength,
including stainless steel, may be used.
[0034] The magnets 14a to 14c are preferably permanent magnets, and holds the stamper 20
by the magnetic force thereof. At least one portion of the magnets 14a to 14c may
be an electromagnet, which generates a magnetic force with a current supplied.
[0035] The holding pad 15a has, for example, a cylindrical structure that is provided with
a hermeticity enhancing mechanism formed at the front end thereof, and that has vacuum
sensor formed therein for detecting a held state of the conveyed object such as stamper
20.
[0036] One end of the head support portion 2 is mounted to a head support portion driving
device (not shown) having a driving source such as a motor so that the power thereof
is transmitted thereto. Also, as shown in Fig. 1, the outside of one surface closed
in the case 3 is adhered to the side surface of the other end side of the head support
portion 2, and one end of the coil spring 4 is held to the inner surface side of the
case 3. The other end side of the coil spring 4 is held to the level difference portion
on the inner wall of the bearing receiver 5b, which holds the outer ring 5aa of the
aligning bearing 5a by another portion of the level difference portion on the inner
wall thereof. As a consequence, the outer ring 5aa of the aligning bearing 5a is held
to the coil spring 4 via the bearing receiver 5b.
[0037] As illustrated in Fig. 1, the inner ring 5ac of the aligning bearing 5a holds the
mounting shaft 6a of the common plate 6. The common plate 6 is disposed so that the
disk-like structure portion thereof is accommodated within the case 3. At this time,
the common plate 6 is arranged so that it is pressurized by the coil spring 4, and
that the inward folded-back portion on the open surface side of the case 3 constitutes
a stopper against this pressurization. Also, the common plate 6 holds one end of the
coil spring 7 at the inside portion of the common plate cylinder portion 6b, while
holds one end of the coil spring 8 at the front end portion of the common plate cylinder
portion 6b.
[0038] As shown in Fig. 1, the coil spring 8 pressurizes the tray 9 by the elastic force
thereof. The tray 9 is arranged so that the inward folded-back portion in the tray
cylinder portion 9a is inserted into the level difference portion on the outer wall
of the common plate cylinder portion 6b, whereby the inserted portion performs the
function of a stopper against the pressurization by the coil spring 8. As a consequence,
the tray 9 is held to the inner ring 5ac of the aligning bearing 5a via the common
plate 6 and the coil spring 8.
[0039] As illustrated in Fig. 1, the magnet 14c and the holding pad 15a is mounted to the
outer peripheral portion of the tray 9, and a suction tube 15c connected to a suction
device for sucking is connected to the holding pad 15a via a suction tube mounting
mechanism 15b.
[0040] As shown in Fig. 1, the other end of the coil spring 7 holds the conveyed object
holding block 10, while the other end of the coil spring 8 holds the tray 9. At this
time, the coil spring 7 pressurizes conveyed object holding block 10 by the elastic
force thereof. The conveyed object holding block 10 is arranged so that the outward
folded-back portion on the open surface side thereof is inserted into the level difference
portion on the inner wall of the common plate cylinder portion 6b, whereby the inserted
portion performs the function of a stopper against the pressurization by the coil
spring 7. As a consequence, the conveyed object holding block 10 is held to the inner
ring 5ac of the aligning bearing 5a via the common plate 6 and the coil spring 7.
[0041] As illustrated in Fig. 1, the magnets 14a and 14b are mounted to the inward folded-back
portion on the open surface side of the conveyed object holding block 10, and the
inside portion of the closed surface of the conveyed object holding block 10 holds
one end of the coil spring 11. The other end of the coil spring 11 holds center guide
12, and the coil spring 11 pressurizes the center guide 12 by the elastic force thereof.
The center guide 12 is arranged so that the outward folded-back portion on the open
surface side thereof is inserted into the inward folded-back portion on the open surface
side of the conveyed object holding block 10, whereby the inserted portion performs
the function of a stopper against the pressurization by the coil spring 11. The reference
pin 13 is adhered to the central portion outside the closed surface of the center
guide 12.
[0042] The holding surface 10a, which is an annular front end portion in the conveyed object
holding block 10, is disposed at a position projecting over the holding surface 9b,
which is the annular held portion of the stamper 20 in the tray 9. The width of this
projection is preferably in the range of 0.8 mm to 1.3 mm, and is more preferably,
in the range of 1.0 mm to 1.1 mm.
[0043] The stamper 20 as a conveyed object is held to the tray 9 and the conveyed object
holding block 10 by the magnetic forces of the magnets 14a to 14c and the suction
force of the holding pad 15a. Here, the stamper 20 is a substantially annular disk
having a central hole, and the stamper 20 held in this manner is positioned with respect
to the tray 9 and the conveyed object holding block 10, by inserting the center guide
12 into the central hole of the stamper 20. Here, the outer diameter of the center
guide 12 and the inner diameter of the central hole of the stamper 20 are preferably
arranged to have sizes such that, when the center guide 12 is inserted into the central
hole of the stamper 20, a gap of approximately 1 to 2 (m is created therebetween.
Also, as described above, by disposing the holding surface 10a of the conveyed object
holding block 10 at a position projecting over the holding surface 9b of the tray
9, the tray 9 holds the outer peripheral portion of the stamper 20, while the conveyed
object holding block 10 holds the inner portion of the stamper 20 at a position projecting
in the direction of the stamper 20 over the stamper holding surface of the tray 9,
preferably in the range of 0.8 mm to 1.3 mm, and more preferably in the range of 1.0
mm to 1.1 mm. The stamper 20 held in this manner is arranged so that the inner peripheral
portion thereof held by the conveyed object holding block 10 becomes convex in the
outward direction (i.e., in the direction from the conveyed object holding block 10
toward the common plate 6), and that the outer peripheral portion thereof held by
the tray 9 warps in the inward direction (i.e., in the direction from the conveyed
object holding block 10 toward the common plate 6), as compared with the inner peripheral
portion thereof.
[0044] Next, descriptions will be made of the mounting operation of the stamper 20 to the
mounting die by the object conveying device 1 according to the present embodiment.
[0045] Figs. 2 to 4 are sectional views of the object conveying device 1 according to the
present embodiment wherein the mounting operation of the stamper 20 to a molding die
30 by this object conveying device 1 is shown.
[0046] As shown in Fig. 2, when mounting the stamper 20 to the molding die 30, first, the
stamper 20 to be mounted is caused to be held to the object conveying device 1 as
described above. Next, by driving the head support portion 2 by a head support portion
driving device (not shown), the stamper 20 is conveyed up to the mounting position
of the molding die 30 (see Fig. 2).
[0047] As illustrated in Fig. 2, the molding die 30 to which the stamper 20 is to be mounted,
has a molding die recess 31, which is a hole into which the reference pin 13 of the
object conveying device 1 is to be inserted for positioning. When the stamper 20 has
been conveyed up to the mounting position of the molding die 30 as described above,
the object conveying device 1 is generally disposed at a position such that the position
of the reference pin 13 thereof deviates from the central axis, which is coaxial with
the molding die recess 31, due to a driving control error of the head support portion
driving device or the like (see Fig. 2). The object conveying device 1 in this embodiment
mounts the stamper 20 held by this device to the molding die 30 while performing an
alignment to eliminate the positional deviation from the central axis.
[0048] When the stamper 20 has been conveyed up to the mounting position of the molding
die 30, the head support portion 2 is now moved to the A direction shown in Fig. 2
by the head support portion driving device (not shown). As the head support portion
2 is moved in the A direction, as shown in Fig. 3, first the front end portion of
the reference pin 13 makes contact with the edge portion of the molding die recess
31. When the head support portion 2 is further continued to be moved, the coil spring
4, which has the lowest elastic force of the coil springs 4, 7 and 11, contracts under
pressure from the edge portion of the molding die recess 31 in contact with the front
end of the reference pin 13. As a result, the bearing receiver 5b, the aligning bearing
5a, the common plate 6 and the like, which have been held by the coil spring 4, moves
to the B direction shown in Fig. 3, and the common plate 6, which has been in contact
with the inward folded-back portion on the open surface side of the case 3, leaves
the case 3, thereby allowing an aligning movement (a movement in the case 3) of the
common plate 6.
[0049] When continuing to move the head support portion 2 in the A direction in this state,
the reference pin 13 in contact with the edge portion of the molding die recess 31
is applied with a force in the C direction shown in Fig. 3. This is because the front
end portion of the reference pin 13 is formed so as to be round off. When the reference
pin 13 is thus applied with the force in the C direction, this force is transmitted
to the common plate 6 via the center guide 12, the coil springs 7 and 11, and the
conveyed object holding block 10. The common plate 6 to which such a force has been
transmitted moves to the F direction shown in Fig. 3, that is, in the direction substantially
parallel to the surface of the molding die 30, by the combination of a substantially
rotating movement of the bearing receiver 5b in the D direction shown in Fig. 3 due
to a deflection of the coil spring 4, and a substantially rotating movement (a substantially
three-dimensional rotating movement) in the E direction shown in Fig. 3 such that
the angle formed by the central axes of the inner ring 5ac and the outer ring 5aa
of the aligning bearing 5a is displaced. When the common plate 6 thus moves to the
F direction, that is, in the direction substantially parallel to the surface of the
molding die 30, the coil springs 7, 8, and 11, the tray 9, the conveyed object holding
block 10, the center guide 12, and the reference pin 13, which are held by the common
plate 6, also moves to the F direction, that is, in the direction substantially parallel
to the surface of the molding die 30. As a consequence, the reference pin 13 is inserted
into the molding die recess 31 while being guided in the central axis direction, and
the stamper 20 is guided to an appropriate position of the molding die 30 in parallel
with the surface of the molding die 30. Guiding the stamper 20 to the appropriate
position of the molding die 30 substantially in parallel with the surface of the molding
die 30 in this way, inhibits the stamper 20 from making contact with the surface of
the molding die 30 in a tilting state, and keeping deformed under the pressure from
the surface.
[0050] When the reference pin 13 is inserted into the molding die recess 31, the center
guide 12 makes contact with the surface of the molding die 30, and further the head
support portion 2 is moved in the A direction, the coil spring 11, which has an elastic
force one rank higher than that of the coil spring 4, now contracts. Consequently,
the center guide 12 held by this coil spring 11 moves in the G direction shown in
Fig. 3. This movement of the center guide 12 is performed until the surface of the
center guide 12 becomes identical with that of the stamper 20, as shown in Fig. 4.
[0051] When the head support portion 2 is further continuously moved in the A direction
after the surface of the center guide 12 has become identical with that of the stamper
20, the coil spring 7, which has an elastic force one rank higher than that of the
coil spring 11, now contracts. When the coil spring 7 contracts, the conveyed object
holding block 10 held to the coil spring 7 pressurizes the inner peripheral portion
of the stamper 20 in the H direction shown in Fig. 4 by the elastic force thereof,
and pressed the inner peripheral portion of the stamper 20 against the molding die
30. Here, the reason why the inner peripheral portion of the stamper 20 is first pressed
against the molding die 30 is because, as described above, the stamper 20 is arranged
so that the inner peripheral portion thereof held by the conveyed object holding block
10 becomes convex in the outward direction, and that the outer peripheral portion
thereof held by the tray 9 warps in the inward direction, as compared with the inner
peripheral portion.
[0052] When the head support portion 2 is further continuously moved in the A direction,
the coil spring 8 now contracts. When the coil spring 8 contracts, the tray 9 held
to the coil spring 8 pressurizes the outer peripheral portion of the stamper 20 in
the I direction shown in Fig. 4 by the elastic force thereof, and pressed the outer
peripheral portion of the stamper 20 against the molding die 30.
[0053] In this manner, first by pressing the inner peripheral portion of the stamper 20
that has become convex in the outward, against the molding die 30, and then by pressing
the outer peripheral portion of the stamper 20 against the molding die 30, it is possible
to dispose the stamper 20 on the molding die 30, while centering the stamper 20 with
respect to the central axis positioned by inserting the reference pin 13 into the
molding die recess 31.
[0054] Even when the stamper 20 has caused deflection because the inner peripheral portion
of the stamper 20 is pressed against the molding die 30 by the elastic force of the
coil spring 7, and then the outer peripheral portion of the stamper 20 is pressed
against the molding die 30 by the elastic force of the coil spring 8, it is possible
to mount the stamper 20 to the molding die 30 by correcting the deflection while relieving
the deflection outside the stamper 20.
[0055] By pressing the inner and outer peripheral portions of the stamper 20 against the
molding die 30 in this manner, the stamper 20 is applied with a force that makes the
stamper 20 parallel to the surface of the molding die 30. The force thus applied is
accommodated by the deflection of the coil spring 4 and the three-dimensional rotation
of the aligning bearing 5a, thereby allowing the stamper to be made parallel to the
surface of the molding die 30, without deforming the stamper 20 by the applied force.
[0056] With the stamper 20 thus pressed against the molding die 30, the holding of the stamper
20 by the holding pad 15a and the magnets 14a to 14c is now released. This releases
the stamper 20 from the object conveying device 1, thereby completing the mounting
of the stamper 20 to the molding die 30. Here, by strengthening the suction force
of the holding pad 15a when holding the stamper 20 to an extent such as to hold the
stamper 20 only by this suction force, and by maintaining the strength of the magnetic
forces of the magnets 14a to 14c to an extent such as to assist the holding of the
stamper 20 by the holding pad 15a, it is possible to detach the stamper 20 only by
switching on/off the suction device.
[0057] In this way, in the present embodiment, since the object conveying device 1 is equipped
with the coil spring 4 held to the case 3, the aligning bearing 5a, of which the outer
ring 5aa is held to the coil spring 4, the tray 9 and the conveyed object holding
block 10, which are held to the inner ring 5ac of the aligning bearing 5a and which
hold the stamper 20, the flexibilities of the tray 9 and the conveyed object holding
block 10 can be enhanced, and when the reference pin 13 is guided into the molding
die recess 31 at the mounting of the stamper 20 to the molding die 30, the contact
portion between the reference pin 13 and the molding die recess 31 can be inhibited
from being subjected to a large force more than is necessary. This allows the stamper
20 to be mounted to the predetermined position while aligning it, without deforming
or damaging the reference pin 13 and/or the molding die recess 31.
[0058] Also, since the object conveying device 1 is equipped with the coil spring 4 held
to the case 3, the aligning bearing 5a, of which the outer ring 5aa is held to the
coil spring 4, the tray 9 and the conveyed object holding block 10, which are held
to the inner ring 5ac of the aligning bearing 5a and which hold the stamper 20, the
tilting of the stamper 20 with respect to the surface of the molding die 30 can be
accommodated by the coil spring 4 and the aligning bearing 5a, at the mounting of
the stamper 20 to the molding die 30. This allows the stamper 20 to be inhibited from
deformation and/or damage caused by its being pressed against the molding die 30 in
a tilting state.
[0059] Furthermore, in this embodiment, since the conveyed object holding block 10 is held
by the coil spring 7, and the tray 9 is held by the coil spring 8, it is possible
to absorb the shock by the coil springs 7 and 8 when the stamper 20 abuts against
the surface of the molding die 30 in a tilting state, at the mounting of the stamper
20 to the molding die 30, thereby allowing the stamper 20 to be inhibited from deformation
and/or damage caused by its abutting against the molding die 30 in a tilting state.
[0060] Moreover, in this embodiment, since the elastic force of the coil spring 4 is set
to be lower than that of the coil spring 11, when the reference pin 13 is pressed
against the edge portion of the molding die recess 31 of the molding die 30, the coil
spring 4 contracts before the coil spring coil 11 contracts, under the pressure. As
a result, before the center guide 12 is depressed by the contraction of the coil spring
11, the contraction of the coil spring 4 depresses the common plate 6, thereby releasing
the common plate 6 from the case 3. Consequently, before the stamper 20 goes out of
alignment with the tray 9 and the conveyed object holding block 10 due to the depression
of the center guide 12, it is possible to align the reference pin 13 and mount the
stamper 20 to an appropriate position of the molding die 30.
[0061] Furthermore, in this embodiment, since the holding surface 10a of the conveyed object
holding block 10 is disposed at a position projecting over the holding surface 9b
of the tray 9, the inner peripheral portion of the stamper 20 can be made convex in
the outward direction, and the outer peripheral portion thereof can be disposed so
as to warp in the inward direction as compared with the inner peripheral portion thereof.
Thereby, the outer peripheral portion of the stamper 20 can be pressed against the
molding die 30 after the inner peripheral portion thereof has first been pressed against
the molding die 30, which has become convex. As a consequence, the stamper 20 can
be disposed on the molding die 30 while centering the stamper 20 with respect to the
central axis positioned by inserting the reference pin 13 into the molding die recess
31.
[0062] Also, in this embodiment, since the holding surface 10a of the conveyed object holding
block 10 is disposed at a position projecting over the holding surface 9b of the tray
9, the inner peripheral portion of the stamper 20 can be made convex in the outward
direction, and the outer peripheral portion thereof can be disposed so as to warp
in the inward direction as compared with the inner peripheral portion thereof. Thereby,
it is possible to press the outer peripheral portion of the stamper 20 against the
molding die 30 after the inner peripheral portion thereof has first been pressed against
the molding die 30, which has become convex. As a result, even when the stamper 20
generates deflection, the stamper 20 can be mounted on the molding die 30 by correcting
the deflection while relieving the deflection outside the stamper 20.
[0063] The present invention is not limited to the above-described embodiment. For example,
in this embodiment, the arrangement is such that the outer ring 5aa of the aligning
bearing 5a is held by the coil spring 4 via the bearing receiver 5b, and that the
common plate 6 is held by the inner ring 5ac of the aligning bearing 5a. Alternatively,
however, the arrangement may be such that the inner ring 5ac of the aligning bearing
5a is held by the coil spring 4, and the common plate 6 is held by the outer ring
5aa of the aligning bearing 5a. In this case, the tray 9 and the conveyed object holding
block 10 are held by the outer ring 5aa of the aligning bearing 5a via the common
plate 6 and the coil springs 7 and 8.
[0064] In this embodiment, the stamper 20 has been taken as an example of conveyed object.
However, the preset invention may be applied to the conveyance of other objects such
as optical disks.
[0065] Next, a second embodiment according to the present invention will be described.
[0066] The second embodiment is a modification of the first embodiment. The second embodiment
is different from the first embodiment in that there is provided a coil spring for
inhibiting the common plate 6 from hanging down. Hereinafter, descriptions will be
mainly made of the differences of the second embodiment from the first embodiment.
Here, matters of the second embodiment common with the first embodiment are omitted
from description.
[0067] Fig. 5 is a sectional view showing the configuration of an object conveying device
40 according to the present embodiment, and Fig. 6 is a sectional view showing the
VI-VI section in Fig. 5. Here, portions common with the first embodiment in Figs.
5 and 6 are designated by the same reference numerals as those in Fig. 1.
[0068] Referring to Fig. 5, the object conveying device 40 comprises the support portion
2; the case 3; the aligning bearing 5a; the bearing receiver 5b; the common plate
6; the coil springs 4, 7, 8, and 11; the conveyed object holding block 10; the center
guide 12; the reference pin 13; the tray 9; the magnets 14a to 14c; the holding pad
15a, the suction tube mounting mechanism 15b, the suction tube 15c; and in addition,
coil springs 41a to 41c, which is fifth elastic members for inhibiting the common
plate 6 from hanging down; and spring guide bolts 42a to 42c for holding the coil
springs 41a to 41c.
[0069] The coil springs 41a to 41c are, for example, the same helical springs as those in
the first embodiment. In this embodiment, although coil springs are used as elastic
members, plate springs or other springs may be employed as elastic members.
[0070] As shown in Fig. 6, the spring guide bolts 42a to 42c are, for example, bolts each
having a shape such that cylinders mutually different in the outer diameter are coaxially
combined. Taking advantage of the differences in the outer diameter, level difference
portions 42aa, 42ba, and 42ca are formed. For example, in the case of the spring guide
bolt 42a, at one end of the front end portion 42ab, which is a cylindrical portion
having the smallest outer diameter, there is provided an intermediate portion 42ac,
which is a cylindrical portion having a secondly small outer diameter, and a rear
portion 42ad, which is a substantially hexagonal columnar portion having the largest
outer diameter, is provided on the other end side of the above-mentioned intermediate
portion 42ac. For example, the front end portion 42ab, the intermediate portion 42ac,
and the rear portion 42ad are coaxially disposed, and the level difference portion
42aa is formed by the difference in the outer diameter between the front end portion
42ab and the intermediate portion 42ac. With regard to such arrangements, the same
goes for spring guide bolts 42b and 42c having front end portions 42bb and 42cb, intermediate
portions 42bc and 42cc, and rear portions 42bd and 42cd, respectively. As shown in
Fig. 6, the lengths of the front end portions 42ab, 42bb and 42cb is preferably arranged
so that, when the spring guide bolt 42a is mounted to the case 3, the tip of each
of the front end portions 42ab, 42bb and 42cb does not reach the bottom surface of
the common plate 6. The material constituting spring guide bolts 42a to 42c is not
particularly limited. Any material that has some degree of strength, including stainless
steel, may be used.
[0071] As illustrated in Fig. 6, spring holding holes 6ca to 6cc into which one-side ends
of the coil springs 41a to 41c are to be mounted, respectively, are formed on the
bottom side of the common plate 6. The shapes of the spring holding holes 6ca to 6cc
are not particularly limited. Any shapes of these spring holding holes into which
the one-side ends of the coil springs 41a to 41c can be inserted, including cylindrical
shape, may be used.
[0072] As shown in Fig. 6, the spring guide bolts 42a to 42c are inserted to the bottom
surface of the case 3, with a substantially uniform spacing thereamong. The front
end portions 42ab, 42bb and 42cb of the spring guide bolts 42a to 42c are inserted
into the one-side ends of the coil springs 41a to 41c, respectively, and the one-end
sides of the coil springs 41a to 41c into which the front end portions 42ab, 42bb
and 42cb of the spring guide bolts 42a to 42c have been inserted, are held by the
level difference portions 42aa, 42ba, and 42ca, respectively. The other ends of the
coil springs 41a to 41c are inserted into the spring holding holes 6ca, 6cb, and 6cc,
and are held thereby, respectively.
[0073] Next, the operation of the object conveying device 40 according to the present embodiment
will be described.
[0074] The operation of the object conveying device 40 is fundamentally the same as that
of the object conveying device 1 according to the first embodiment. The present embodiment
is different from the first embodiment in that, when the coil spring 4 contracts and
the common plate 6 is released from the case 3, the lower portion of the common plate
6 is held by the coil springs 41a to 41c. As can be seen from Fig. 6, the holding
of the lower portion of the common plate 6 in this case is performed only by the coil
springs 41a to 41c, and not by the spring guide bolts 42a to 42c. This prevents the
common plate 6 from being fixed by the spring guide bolts 42a to 42c, thereby securing
the flexibility of the common plate 6.
[0075] In this manner, by holding the lower portion of the common plate 6 by the coil springs
41a to 41c, the coil spring 4 contracts, and thereby it is possible to prevent the
common plate 6 from hanging down when having become free, while securing flexibility
of the common plate 6.
[0076] The present invention is not limited to the above-described embodiments. In this
embodiment, the arrangement is such that the lower portion of the common plate 6 is
held by the coil springs 41a to 41c to prevent the common plate 6 from hanging down.
Alternatively, however, the arrangement may be, for example, such that, by adhering
the one-side ends of these coil springs to the inner side surface of the case 3 (i.e.,
the connection portion side between the head support portion 2 and the case 3) and
adhering the other ends thereof to the side surface of the common plate 6 (i.e., the
surface where the mounting shaft 6a is provided), the common plate 6 is held from
the side surface thereof, thereby suppressing the hanging down of the common plate
6.
[0077] As is evident from the foregoing, the object conveying device according to the present
invention is arranged to comprise a support portion that is provided with a power
to move a conveyed object; a first elastic member held to the support portion; an
aligning bearing wherein one of an inner ring and an outer ring thereof is held to
the first elastic member; and a conveyed object holding mechanism that holds the conveyed
object, the conveyed object holding mechanism being held to one end of the ring that
is not held to the first elastic member out of the inner and outer rings of the aligning
bearing. Therefore, the conveyed object can be mounted to the predetermined position
while aligning it, without deforming or damaging the reference pin and/or the molding
die.
[0078] Also, since the object conveying device according to the present invention is arranged
to comprise the support portion that is provided with a power to move the conveyed
object; the first elastic member held to the support portion; the aligning bearing
where one of the inner ring and the outer ring thereof is held to the first elastic
member; and the conveyed object holding mechanism that holds the conveyed object,
the conveyed object holding mechanism being held to one end of the ring that is not
held to the first elastic member out of the inner and outer rings of the aligning
bearing, it is possible to mount the conveyed object to the predetermined position
while aligning it, without deforming or damaging the conveyed object.
[0079] While the present invention has been described with reference to what are at present
considered to be the preferred embodiments, it is to be understood that various changes
and modifications may be made thereto without departing from the invention in its
broader aspects and therefore, it is intended that the appended claims cover all such
changes and modifications that fall within the true scope of the invention.